The present invention relates to a canister attachment construction of a vehicle. In particular, the present invention relates to a canister attachment construction, wherein the canister is installed on the right side of the vehicle in a region surrounded by a central cross member, which is positioned at approximately the central region of the vehicle frame, a cross member that is positioned behind this central cross member, and a side frame. The present inventions relates to a canister attachment construction wherein the length of the vapor pipe, which connects the canister to the fuel tank, is shortened. Furthermore, the present invention relates to a canister attachment construction wherein the canister is made larger in order to ensure an adequate adsorption amount. Since the canister of the present invention is not placed in the engine compartment of the vehicle, the engine compartment is simplified, and there is no risk of reduced adsorptive function due to warming of the canister.
A conventional vehicle has a canister to sorb and retain evaporated fuel generated inside a fuel tank. The canister supplies this retained evaporated fuel to the intake system of an internal combustion engine.
The canister is controlled so that, for example, when the internal combustion engine is stopped, the canister sorbs and retains evaporated fuel which is generated inside a fuel tank. In addition, when the internal combustion engine is running, the evaporated fuel that has been sorbed and retained is released supplied to the intake system of the internal combustion engine.
A conventional vehicle canister attachment construction described above is disclosed in Japanese Laid-Open Patent Publication No. 5-193522. In the under body construction of the car disclosed in this publication, a transfer and a canister are disposed underneath the floor of the car body. The canister is placed along the retreating path of the transfer. A support construction is used, in which, at the time of a collision of the vehicle, the canister is displaced to the side of the retreating pathway of the transfer. A large volume canister, which uses the open space in back, is installed on the transfer underneath the floor of the car body.
In addition, another conventional canister attachment construction is disclosed in Japanese Laid-Open Patent Publication Number 8-142693. In the canister attachment construction disclosed in this publication, a canister is filled with adsorbent to sorb evaporated fuel generated inside a fuel tank. The canister is disposed at an approximately central region of a cross member that connects between the rear side members on either side of the vehicle. The canister is attached at a part with the least vibration, to prevent the wearing of the adsorbent within the canister.
In addition, another conventional canister attachment construction is disclosed in Japanese Laid-Open Patent Publication Number 8-230493. In this publication, there is disclosed a evaporated fuel treatment device for a vehicle, wherein a vehicle is equipped with a frame, which constructs the car body. The frame includes a pair of right and left side members, which construct the rear part of the car body. A cross member connects both side members together. An exhaust pipe, passing exhaust gas emitted from the engine, is positioned near the side members and cross member. A canister is disposed in the space surrounded by the side members, cross member, and exhaust pipe. Fuel is efficiently released from the adsorbent within the canister.
In addition, another conventional canister attachment construction is disclosed in Japanese Examined Patent Publication Number 2535338. The placement construction of the canister disclosed in this publication is in a region surrounded by right and left side members, the upright part of the rear floor panel, and a placing member in the car crosswise direction of a rear suspension. The canister is disposed on the opposite side of the exhaust tube, which has been displaced to one side of the car in the crosswise direction.
In addition, another conventional canister attachment construction is disclosed in Japanese Examined Utility Model Publication Number 6-8897. In the fuel tank canister disclosed in this publication, the fuel tank as well as the canister, which is attached and supported via brackets near the fuel tank, are placed on the underside of the floor within an area surrounded by a pair of rear frames, which are placed on the underside of the floor at the rear of a vehicle. A pair of cross members are placed between the rear frames. This arrangement is advantageous for protecting the canister.
In addition, another conventional canister attachment construction is disclosed in Japanese Laid Open Utility Model Publication 2557012. In the car canister attachment construction of this publication, the canister is attached to a spare tire mount at the rear of the car body. A pipe connected to the canister extends in the cross direction of the car body from the canister, in the forward direction of the car body along the rear side frame. The pipe is anchored to the spare tire mount by a first fastening member. At a certain distance in the front-rear direction of the car body, the pipe is fastened to the rear side frame or to a car body member near it by a second fastening member and a third fastening member. Between the second and third fastening members, a bending part is formed in the down direction of the car body. There is no danger of the pipe falling off of the canister while the vehicle is moving.
Referring to FIGS. 5, 6 and 7, conventional canister attachment constructions of a vehicle include a canister 124,224 attached via brackets to front wheel housing panels 152,252 inside an engine compartment on the vehicle front side.
A car body frame 104 of vehicle 102 has a construction including right and left side frames 110-2 (the disclosure of the left side frame is omitted). A subframe 112 is positioned between side frames 110-2. A plurality, preferably five, cross members 114-3, 114-4, and 114-5 (the disclosure of first and second cross members is omitted) are positioned between side frames 110-2.
On one side of the vehicle, preferably the left side, an exhaust pipe extends from the vehicle front side towards the vehicle rear side. A fuel tank 128 is positioned on the vehicle rear side. On the other side of the vehicle, preferably the vehicle right side, a vapor pipe 154 connects fuel tank 128 to canisters 124, 224. A fuel supply pipe 134 supplies fuel from fuel tank 128 to an injector (not shown). A fuel return pipe 136 returns fuel from the injector to fuel tank 128.
For the conventional canister described above, there are various constructions depending on the adsorption amount. For example, referring specifically to FIG. 6, there is a canister construction where the top of canister 124 connects to vapor pipe 154, which connects fuel tank 128 with canister 124. A purge hose connects canister 124 with the intake system of the internal combustion engine. The bottom of canister 124 connects to a canister air hose 132.
Referring specifically to FIG. 7, there is a canister construction where the top of canister 224 connects to a purge hose, which connects canister 224 with the intake system of the internal combustion engine. A canister air hose 232 also connects with the top of canister 224. The bottom of canister 224 connects to a vapor pipe, which connects the fuel tank with canister 224.
As a result, the length of the vapor pipe, which connects the fuel tank with the canister, becomes long. This construction makes it difficult for the evaporated fuel generated inside the fuel tank to be adequately sorbed and retained by the canister. This construction also makes it easier for the evaporated fuel to be released into the atmosphere when refueling and the like.
In addition, by attaching the canister to the inside of the engine room of a vehicle, the atmospheric temperature is raised, and the adsorptive performance of the canister may be reduced.
Furthermore, for example, when an external force acts from the front side of the vehicle, such as during a front end collision, the internal combustion engine moves towards the rear of the vehicle due to this external force. In order to prevent the front wheel housing panel from being pushed by the internal combustion engine and breaking the canister, there needs to be a procedure for strengthening the canister perimeter members or a procedure for having some other form of reinforcing members. This increases the overall manufacturing costs of the vehicle.